Tag: maths

Quizzes (518) Questions (9324)

Questions Related to maths

Multiple choice maths introduction to set cardinal number of a finite set cardinality of a set representation of sets

In a group of children $35$ play football out of which $20$ play football only, $22$ play hockey; $25$ play cricket out of which $11$ play cricket only. Out of these $7$ play cricket and football but not hockey, $3$ play football and hockey but not cricket and $12$ play football and cricket both. How many play all three games?

  1. $5$
  2. $2$
  3. $12$
  4. $60$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let $F,H$ and $C$ denote the no. of children who play Football, Hockey and Cricket respectively.
Given $n(F)=35,n(H)=22,n(C)=25$ and $n(F\cap C\cap H^{\prime})=7,n(F\cap H\cap C^{\prime})=3,n(F\cap C)=12$
but $n(F\cap C\cap H^{\prime})=n(F\cap C)-n(F\cap C\cap H)$
$\Rightarrow 7=12-n(F\cap C\cap H)$
$\Rightarrow n(F\cap C\cap H)=5$
$\therefore$ No of children who play all three games is $5$
Hence, option A

Multiple choice addition and subtraction vedic methods of multiplication vedic mathematics history of mathematics maths

If $A, {A} _{1}, {A} _{2}, {A} _{3}$ be the area of the in-circle and ex-circles, then $\dfrac {1}{\sqrt {{A} _{1}}}+\dfrac {1}{\sqrt {{A} _{2}}}+\dfrac {1}{\sqrt {{A} _{3}}}$ is equal to

  1. $\dfrac {1}{\sqrt {{A}}}$
  2. $\dfrac {2}{\sqrt {{A}}}$
  3. $\dfrac {3}{\sqrt {{A}}}$
  4. $None$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$A _1={\pi}{r _1}^{2}=\dfrac{{\pi}{\Delta^{2}}}{(s-a)^{2}}$

$A _2={\pi}{r _2}^{2}=\dfrac{{\pi}{\Delta^{2}}}{(s-b)^{2}}$
$A _3={\pi}{r _3}^{2}=\dfrac{{\pi}{\Delta^{2}}}{(s-c)^{2}}$
$A={\pi}{r}^{2}=\dfrac{{\pi}{\Delta^{2}}}{(s)^{2}}$
$\dfrac{1}{\sqrt{A _1}}+\dfrac{1}{\sqrt{A _2}}+\dfrac{1}{\sqrt{A _3}}=\dfrac{1}{\sqrt{\pi}}\bigg[\dfrac{s-a}{\Delta}+\dfrac{s-b}{\Delta}+\dfrac{s-c}{\Delta}\bigg]=\dfrac{1}{\sqrt{\pi}\Delta}[3{s}-(a+b+c)]=\dfrac{s}{\sqrt{\pi}\Delta}=\dfrac{1}{\sqrt{A}}$

Multiple choice addition and subtraction vedic methods of multiplication vedic mathematics history of mathematics maths

Subtract $347657$ by $238294$ using vinculum numbers.

  1. $109363$
  2. $100363$
  3. $109373$
  4. $109563$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

1) The first thing we do is write these numbers one on top of the other.

347657
238294

2) Now we just start subtracting vertically, and whenever our number is negative we represent it as a vinculum number.

347657
238294

3) This next subtraction is 7 – 8 = -1…so we just write this as 1 and continue on.

347657
238294
1 1 1 443

4) The ‘1‘ and ‘4‘ here are considered as two separate groups (since theres a non-vinculum number in-between them), so each is subtracted from 10. This has the effect of reducing the “previous one” by one.

109363